Password Security

I normally use X-Notifier Reloaded with Firefox 56.  When I start the browser, it asks for my "Master Password".  If I enter it, X-Notifier works fine, if I don't then X-Notifier does not see any of my email accounts and doesn't work until I reload the browser and enter my Master Password.

 

I recently tried the current version of the Firefox browser and the latest X-Notifier (4.x).  When I start the browser, it does not ask for my "Master Password" (even though it is set) and all my email accountss are there in X-Notifier.  If I select them, it logs me in to each account.

So, I am wondering if this is expected?  Should I be able to automatically log in to all the email accounts without having to enter the "Master Password"?  If it is how it is supposed to work, isn't it a security problem?  At least it appears that the old version on Firefox 56 did not allow you to log in to email unless you entered your Master Password.

I understand that Chrome does not protect passwords once you are logged in to windows.  If you are logged in to windows, then all passwords are viewable, but I thought Firefox was different, but now I am not so sure.

Master Passoword is specifically to protect website logins.
If I remember correctly, I think the changes to Firefox that forced creation of X-Notifier 4.x... also resulted in not being able to use Master Password the same way for X-Notifier.